About Munish Gupta

Munish K Gupta is a senior architect working in a leading IT services company. His experience is in building Online Portals, SaaS Platforms, CRM Solutions and Transaction Processing Systems. He is author of the book - Akka Essentials.

Implementing Master Slave / Grid Computing Pattern in Akka

Master Slave pattern is a prime example of fault tolerance and parallel computation. The idea behind the pattern is to partition the work into identical sub tasks which are then delegated to Slaves. These slave node or instances will process the work task and send back the result to the master. The master will then compile the resultsreceivedfrom all the slave nodes.Key here is that the Slave nodes are only aware on how to process the task and not aware of what happens to the output.

The Master Slave pattern is analogous to the Grid Computing pattern where a control node distributes the work to other nodes. Idea is to make use of the nodes on the network for their computing power. SETI@Home was one of the earliest pioneers in using this model.

I have build a similar example with difference being that worker nodes get started on Remote Nodes, Worker Nodes register with Master(WorkServer) and then subsequently start processing work packets. If there is no worker slave registered with Master(WorkServer), the master waits the workers to register. The workers can register at any time and will start getting work packets from there on.

The example demonstrates how an WorkerActor system sends a request for registration. The RegisterRemoteWorker recieves the request and forwards the same to JobController where the RoundRobinRouter is updated for the new worker information. The WorkScheduler sends a periodic request to JobController, who then sends packets to all the registered worker actors.

The example does not implement fault tolerance with respect to on how to handle failures when the remote actors die or how to re-process packets that have not been processed. Similarly, there may be cases where the remote worker actors might want to shutdown after processing certain amount of packets, they can then indicate to the master to stop giving them work. I will add fault tolerance soon!

Updated: Code base updated to handle worker shutdowns. If the remote actors die or shut down, the JobController detects thefail-oversusing remote actorlistenersand updates the router.

The code base for the program is available at the following location – https://github.com/write2munish/Akka-Essentials under the GridPatternExample

Reference: Implementing Master Slave / Grid Computing Pattern in Akka from our JCG partner Munish K Gupta at the Akka Essentials blog.

Related Whitepaper:

Functional Programming in Java: Harnessing the Power of Java 8 Lambda Expressions

Get ready to program in a whole new way!

Functional Programming in Java will help you quickly get on top of the new, essential Java 8 language features and the functional style that will change and improve your code. This short, targeted book will help you make the paradigm shift from the old imperative way to a less error-prone, more elegant, and concise coding style that’s also a breeze to parallelize. You’ll explore the syntax and semantics of lambda expressions, method and constructor references, and functional interfaces. You’ll design and write applications better using the new standards in Java 8 and the JDK.

Get it Now!  

One Response to "Implementing Master Slave / Grid Computing Pattern in Akka"

Leave a Reply


eight − 4 =



Java Code Geeks and all content copyright © 2010-2014, Exelixis Media Ltd | Terms of Use | Privacy Policy
All trademarks and registered trademarks appearing on Java Code Geeks are the property of their respective owners.
Java is a trademark or registered trademark of Oracle Corporation in the United States and other countries.
Java Code Geeks is not connected to Oracle Corporation and is not sponsored by Oracle Corporation.

Sign up for our Newsletter

20,709 insiders are already enjoying weekly updates and complimentary whitepapers! Join them now to gain exclusive access to the latest news in the Java world, as well as insights about Android, Scala, Groovy and other related technologies.

As an extra bonus, by joining you will get our brand new e-books, published by Java Code Geeks and their JCG partners for your reading pleasure! Enter your info and stay on top of things,

  • Fresh trends
  • Cases and examples
  • Research and insights
  • Two complimentary e-books